1. Field of Invention
The present invention relates to a lighting lamp control technology, and more particularly to a method for driving light adjustments, a device therefor and a light adjustable lamp comprising the device, wherein the device is in a combination with an on-off switch to control and adjust brightness of a light source.
2. Description of Related Arts
Under an increasing shortage of energy resources, the energy saving of the lamps are becoming more and more important. Conventionally, the energy saving of lighting lamps mainly aims at replacing conventional incandescent lamps with energy-saving lamps, such as the fluorescent lamps and the LED, and pays little attention to the light adjustment technology which effectively saves energy by duly adjusting brightness of the lamps. On one hand, researches about the light adjustment technology are few; on the other hand, consumers have the demand of light adjustment technology, but have no technical supports. When purchasing the lighting lamps, the consumers are always bothered about choosing what power of the lamps to satisfy lighting demand; and after the lamps with certain power are purchased, a dilemma that most of such high power is unnecessary often occurs. Moreover, the conventional home lighting lamps only have switching functions without light adjustments and thus the lamps have to be switched on even if only dim light is demanded, which results in a great waste. Existing bedside lamps at some hotels have functions of adjusting brightness, but the brightness adjustments are accomplished via knobs, which is basically impossible for home lighting because most existing home walls are only installed with on-off switches, instead of the knobs, to switch off the lamps. Further, if the knobs are used for the light adjustments, the common on-off switches are required to be replaced with the knobs, which adds many engineering costs; because of potential danger of electric shock during replacing the switches, professional electricians are needed to do the replacing, which undoubtedly further adds labor cost of the replacing; and the on-off switches are abandoned while the knobs are used, which further increases product costs of the knobs. As a result, such a light adjustment technology is hardly widely applied on market unless for the lighting construction to-be-started. Some relatively advanced remote control light adjustment technologies also appear on market. The remote control light adjustment technologies require no extra construction and no labor costs of replacing, but it is difficult to keep remote controllers and turning on the lamps often fails because of the drained remote controllers.
The field of commercial lighting has the demand not only for the brightness adjustments, but also for color adjustments. Similarly, the color adjustments also require providing additional controlling devices rather than the on-off switches, which adds the costs of the light adjustment. Certainly, the home lighting also has potential demand of the color adjustments, but no conventional color adjustment technology via the on-off switches ever appears.
A Chinese patent having an application number of 200810135921.3, searched out by the inventor, discloses a device for driving light adjustments and a method therefor. The device cooperates with an LED driver and changes brightness via calculating a frequency of a switch switching between ON and OFF, so as to enable the LED driver to adjust light. The device is only able to discretely adjust the brightness because of calculating the frequency of the switch switching between ON and OFF to change the brightness. The brightness can be divided into several grades and each grade of brightness corresponds to a certain frequency of the switch switching between ON and OFF by the switch. The device is unable to linearly and freely adjust the brightness. Meanwhile, the brightness adjustment requires frequently switching between ON and OFF, leading to frequent lightening and extinguishing of LED lamps, which is cumbersome and uncomfortable for human eyes and, more importantly, reduces service lives of the lamps.